Integrated circuits (ICs) are susceptible being damaged by static electricity. Generally, protection circuits can be configured on the circuit input/output terminals or on power protection devices to prevent the internal circuitry from being damaged by static electricity.
In the existing integrated circuit design, electrostatic discharge (ESD) protection structure is usually used to reduce the static electricity damage. The existing ESD protection structure mainly include gate-grounded N-type field effect transistor (GGNMOS) protection circuit, silicon controlled rectifier (SCR) protection circuit, lateral double diffusion field-effect transistors (LDMOS) protection circuit, bipolar junction transistor (BJT) protection circuit, etc.
The GGNMOS is a widely used electrostatic discharge protection structure. Since the power consumption of the MOS tube is a product of the current and the voltage drop, under certain ESD static current, if the voltage drop on the MOS tube can be reduced, the junction temperature of the MOS tube can also be reduced, thereby protecting the MOS. As an ESD device, in a forward direction, the GGNMOS depends on the parasitic NPN BJT to discharge the ESD current. The NPN includes an N+ active region of the drain, a P-type substrate, and the N+ active region of the source. A path for discharging the ESD current in a reverse direction includes a PN diode and an NMOS diode connected to the gate source. The PN diode includes a P-type substrate and an N+ active region.
In a full-chip ESD network, when an ESD time is arrived, the GGNMOS may be turned on in both forward direction and reverse direction, which depends on the potential ESD path, because the ESD current always flows to the low-impedance path. Thus, the ESD performance of the GGNMOS in both forward direction and reverse direction should be considered in the design to ensure the reliability of integrated circuits. As a BJT, the GGNMOS has a breakdown working mechanism, the ESD current is discharged depending on a low resistance path formed by a trigger of an avalanche breakdown between the drainregion and the substrate.
However, the performance of the existing electrostatic discharge protection structure needs to be improved. Accordingly, the disclosed item management system and method are directed to solve one or more problems set forth above and other problems.